1. Field of Invention
The present invention relates generally to the field of wireless communication and data networks. More particularly, in one exemplary aspect, the present invention is directed to methods and apparatus for optimizing paging transmissions in a wireless communication and data network based on mobile device context information.
2. Description of Related Technology
Universal Mobile Telecommunications System (UMTS) is an exemplary implementation of a “third-generation” or “3 G” cellular telephone technology. The UMTS standard is specified by a collaborative body referred to as the 3rd Generation Partnership Project (3GPP). The 3GPP has adopted UMTS as a 3G cellular radio system targeted for inter alia European markets, in response to requirements set forth by the International Telecommunications Union (ITU). The ITU standardizes and regulates international radio and telecommunications. Enhancements to UMTS will support future evolution to fourth generation (4G) technology.
A current topic of interest is the further development of UMTS towards a mobile radio communication system optimized for packet data transmission through improved system capacity and spectral efficiency. In the context of 3GPP, the activities in this regard are summarized under the general term “LTE” (for Long Term Evolution). The aim is, among others, to increase the maximum net transmission rate significantly in the future, namely to speeds on the order of 300 Mbps in the downlink transmission direction and 75 Mbps in the uplink transmission direction.
Further advancements of 3GPP are being investigated within LTE towards an IMT-Advanced radio interface technology, referred to as “LTE-Advanced” or “LTE-A”. Details regarding scope and objectives of the LTE-Advanced study are described at, inter alia; RP-080137 entitled “Further advancements for E-UTRA (LTE-Advanced)” to NTT DoCoMo et al., the contents of which are incorporated herein by reference in its entirety. The IMT-Advanced activities have been commenced and are guided by ITU-R (International Telecommunications Union-Radio Communication Sector). Key features to be supported by candidate IMT-Advanced systems have been set by ITU-R and include amongst others: (1) high quality mobile services; (2) worldwide roaming capability; and (3) peak data rates of one hundred (100) Mbps for high mobility environments, and of one (1) Gbps for low mobility environments.
The current discussions in 3GPP related to LTE-A are focused on the technologies to further evolve LTE in terms of spectral efficiency, cell edge throughput, coverage and latency based on the requirements in 3GPP TS 36.913: “Requirements for further advancements for E-UTRA (LTE-Advanced)”, the contents of which are incorporated herein by reference in its entirety. Candidate technologies include (1) multi-hop Relay; (2) downlink network Multiple Input Multiple Output (MIMO) antenna technologies; (3) support for bandwidths greater than twenty (20) MHz by spectrum aggregation; (4) flexible spectrum usage/spectrum sharing; and (5) intercell interference management. Backward compatibility with legacy LTE networks is also an important requirement for future LTE-A networks, i.e. an LTE-A network also supports LTE User Equipment (UE), and an LTE-A UE can operate in an LTE network.
Prior Art Paging Mechanisms—
Paging mechanisms are used in many prior art cellular mobile radio communication systems such as UMTS and LTE. Paging mechanisms allow a mobile device to minimize power consumption by operating in a reduced or “idle” state while unused. Once a UE receives a paging notification, it “wakes up” to respond to the notification.
Various approaches to paging mechanisms within wireless systems are evidenced in the prior art. For example, within most cellular networks, the network operator maintains an approximate location or “Tracking Area” (TA) for idle mobile devices. Each TA consists of several cells. When a mobile device is paged, all assigned cells within the TA transmit the paging notification. Presumably, as long as the mobile device has not moved out of the TA, it should receive the paging notification. Unfortunately, larger tracking areas that provide better paging coverage also consume proportionately more radio spectrum and resources; thus the prior art solutions trade coverage area for resource utilization.
Incipient LTE-A networks flexibly fragment and/or aggregate spectrum bandwidths freely. Regrettably however, such spectrum flexibility considerably complicates paging; as a UE moves through a tracking area, the bandwidth usage may vary widely. For example, the UE is generally unaware of the resource configuration used for paging messaging. Similarly, the network does not know which resources the UE is monitoring for paging channel reception. Thus, existing networks transmit paging channel messages over the entire cell bandwidth for each cell of the TA, until contact with the mobile device is re-established.
Accordingly, suitable paging mechanisms are needed to specifically address networks having fragmented multi-band operational capabilities, and flexible resourcing. Such an improved solution should ideally operate seamlessly and without adversely impacting user experience on existing radio apparatus, and that of other wireless devices (i.e., remaining backward compatible).
Improved apparatus and methods for paging mechanisms specifically addressing the complexities of the new LTE-Advanced architecture are also needed. The LTE-Advanced system architecture combines fragmented multiband capabilities, OFDM access, and mixed populations of legacy and newer UEs. Existing mechanisms for paging within this architecture are less than optimal.